JP3281161B2 - Water purification equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water purification apparatus in a water purification facility or the like.

[0002]

2. Description of the Related Art Water purification facilities such as water purification plants can cope with relatively wide fluctuations in the quality of treated raw water.
A water purification apparatus using a rapid filtration method is generally used. This water purification treatment device is provided with a sedimentation pond and a filtration pond, and a flocculant is agglomerated by injecting a flocculant into the treated raw water to coagulate turbid substances in the treated raw water.
After the floc has been removed as much as possible by settling in a sedimentation basin, rapid filtration is performed in a filtration basin. Then, the treated water thus filtered is subjected to chlorination and the like, and then sent from a reservoir.

[0003]

However, in such a water purification apparatus using the rapid filtration method, in order to reliably remove floc from the sedimentation basin and to perform efficient filtration in the filtration basin, the sedimentation of these sediments is difficult. A certain area must be ensured in the pond and the filtration pond, that is, the water purification capacity is determined by the installation area of the equipment. For this reason, there was a natural limit in trying to increase the processing capacity in a small space. Also,
Since the filtration treatment is performed in the filtration pond after the treated raw water is subjected to the coagulation sedimentation treatment in the precipitation pond, it is inevitable that much processing time is required. Furthermore, flocs formed by agglomeration of organic components among turbid substances in treated raw water are relatively light and hard to settle, and thus are difficult to remove in a sedimentation basin. Therefore, the conventional water purification apparatus has a problem that it cannot sufficiently cope with treated raw water having a large amount of organic components in turbid matter.

The present invention has been made under such a background, and it is possible to obtain a high water purification capacity even in a small space, to shorten the processing time, and to treat a large amount of organic components. It is an object of the present invention to provide a water purification device capable of effectively removing flocs from raw water.

[0005]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention relates to a flotation treatment apparatus for mixing pressurized water into treated raw water to float flocs in the treated raw water in a floating treatment tank, made by and a membrane filtering device that flocs are filtered by flotation has been treated membrane module raw water by the apparatus, the membrane module by the floating process tank
And it is characterized by being disposed below the inlet of the treated raw water . In addition, the present invention also provides a process for treating raw water with pressurized water
Flotation in the raw water by mixing
And a floating processing device
The raw water separated by flotation is filtered by a membrane module.
And a membrane filtration device,
The membrane is disposed in a processing tank, and is located above the membrane module.
Make sure that the inclined plate is installed so as to cover the module.
And features .

[0006]

In the water treatment apparatus having the above-mentioned structure, the raw water to be treated is mixed with pressurized water (saturated air water) in which air is dissolved at a high concentration under pressure and introduced into the levitation treatment tank of the levitation treatment apparatus. Here, the suspended matter in the raw water to be treated floats on the surface of the floating treatment tank in association with the fine bubbles contained in the pressurized water, is collected as flocs by the recovery device, and is taken out from the floating treatment tank. On the other hand, the treated raw water from which the flocs have been removed in this way stays in the floating treatment tank. In the floating treatment tank, a membrane module of the membrane filtration device is arranged. Is subjected to a membrane filtration treatment and discharged from the floating treatment tank as clean treated water.

As described above, according to the water purification treatment apparatus having the above-described structure, the floc is removed from the raw water to be treated by the flotation treatment apparatus, and the membrane module of the membrane filtration device disposed in the flotation treatment tank of the flotation treatment apparatus. Since the membrane filtration is performed, the space of the apparatus can be saved and the processing time can be reduced. Further, since the flocs are removed by the floating treatment, it is possible to effectively remove even relatively light organic flocs.

[0008]

FIG. 1 shows an embodiment of the present invention. The water purification apparatus of the present embodiment comprises a floating treatment apparatus 1 and a membrane filtration apparatus 2. The levitation processing apparatus 1 further includes a levitation processing tank 3 and a collection device 4 disposed above the levitation processing tank 3. The recovery device 4 is a ring belt type in which a plurality of scraping plates 11 are attached to a chain 12 at regular intervals, and by driving the chain 12 to move the scraping plates 11, The floc F floating on the surface is scraped, taken out of the floating treatment tank 3, and collected. The floc F collected by the collecting device 4 is appropriately subjected to post-processing by a processing device such as a dehydrator (not shown).

On the other hand, an inlet 13 for raw water is provided on the side wall of the floating processing tank 3, and an inlet 14 for the raw water is connected to the inlet 13. The treated raw water that has been subjected to a pretreatment such as injection of a coagulant is supplied to these inflow channels 1
4 and into the floating treatment tank 3 through the inlet 13. A pressurized water passage 15 is connected to the inflow passage 14 via a valve 15A. Pressurized water (saturated air water), which is high-concentration air-dissolved water into which pressurized air is injected into a pressurized water tank (not shown), is provided. The raw water is mixed with the raw water through the pressurized water channel 15 and is introduced into the floating treatment tank 3. The pressurized water channel 15 may be connected to the side wall of the floating treatment tank 3 via a valve 15B as shown in the figure, and the raw water and the pressurized water may be separately introduced into the floating treatment tank 3. In this case, It is preferable to introduce pressurized water from below the raw water to be treated. Further, a guide plate 16 extending in the vertical direction is provided near the introduction port 13 in the floating treatment tank 3 so as to face the introduction port 13, and a floc of treated raw water introduced from the introduction port 13 is provided. The F is encouraged to float.

In the levitation tank 3, a membrane module 21 of the membrane filtration device 2 is provided. The membrane module 21 is a U-shaped module formed by bundling hollow fiber membranes (MF membranes) in a U-shape, and is disposed in the levitation treatment tank 3 so as to be located below the inlet 13. I have. The membrane module 21 is connected to a drainage passage 22 for discharging the treated water subjected to the membrane filtration treatment. The drainage passage 22 is led out of the floating treatment tank 3 and used for chlorination (not shown). It is connected to the post-treatment process of the treated water. Further, a washing channel 23 for backwashing is connected to the drainage channel 22. The washing water is caused to flow back into the drainage channel 22 by a pump 24, so that the membrane module 21 is washed.
Is designed to be backwashed.

An inclined plate 31 is provided above the membrane module 21 in the floating treatment tank 3 so as to cover the membrane module 21 in plan view from above. The inclined plate 31 is inclined so as to gradually rise upward while being curved as it moves away from the introduction port 13 side, and treated raw water containing turbidity introduced into the floating treatment tank 3 from the introduction port 13 directly. It does not flow into the membrane module 21. Below the membrane module 21, an aerator 32 for emptying is disposed so as to face the entire lower surface of the membrane module 21 and spread therethrough. Is connected. At the time of empty washing, compressed air is supplied from the supply passage 33 to the aerator 32, so that air becomes bubbles and flows into the membrane module 21 from the aerator 32, and adheres to the surface of the hollow fiber membrane of the membrane module 21. Has been made to eliminate. Note that, instead of the empty washing, the pressurized water (air-saturated water) may be jetted from below the membrane module 21 to remove the deposits on the membrane surface. Furthermore, the floating treatment tank 3 below the aerator 32
A rectifying plate 34 is provided therein, and a drain discharge passage 35 is connected to the bottom of the floating treatment tank 3 further below the rectifying plate 34.

In the water treatment apparatus having such a configuration, the treated raw water into which the coagulant such as aluminum is injected is sent to the flotation tank 3 of the flotation apparatus 1 through the inflow path 14.
The inlet 13 is mixed with the pressurized water from the pressurized water passage 15
From the floating treatment tank 3. In the introduced treated raw water, turbid matter is aggregated by the flocculant to form flocs F, and fine bubbles due to pressurized water adhere to the flocs F.
Rise to the surface. The flocs F thus floated are separated from the scraping plates 11 of the collecting device 4 as described above.
Is collected and collected. On the other hand, the treated raw water from which the floc F has been removed by the levitation treatment of the levitation treatment device 1 stays in the levitation treatment tank 3 and is subjected to membrane filtration through the hollow fiber membrane of the membrane module 21 of the membrane filtration device 2. It is discharged from the drainage channel 22 as treated water. The discharged treated water is subjected to post-treatment such as chlorine disinfection and then sent. During processing, compressed air is supplied to the aerator 32 from the supply path 33, so that the membrane module 21 is constantly or intermittently washed.

As described above, according to the water purification apparatus having the above-mentioned structure, the raw water introduced into the floating processing tank 3 of the floating processing apparatus 1 has the flocs F removed by the floating processing, and the flocs F are thus removed. The treated raw water is subjected to membrane filtration by the membrane module 21 of the membrane filtration device 2 provided in the same floating treatment tank 3, and is discharged as clean treated water. Therefore, it is possible to save the space of the apparatus, and the treated raw water from which the floc F has been removed by the flotation treatment apparatus 1 is continuously subjected to the membrane filtration processing by the membrane filtration apparatus 2, so that the treatment time is greatly reduced. Can be shortened. Moreover, since the floc F is removed from the treated raw water by the levitation treatment by the levitation treatment apparatus 1, the turbid matter in the treated raw water contains a large amount of organic matter components, and the floc F is hard to settle.
Is formed, such a floc F can be effectively removed. Therefore, it is possible to sufficiently treat the treated raw water containing a large amount of such organic components, and it is possible to adapt to a wider range of fluctuations in the quality of the treated raw water. It is possible to provide a water purification treatment device. Further, in some cases, a sufficient treatment effect can be obtained even in a chemical-free treatment in which a coagulant is not injected into the raw water for treatment.

In this embodiment, the inlet 13 of the raw water is treated.
A guide plate 16 is provided in the vicinity of the floating plate.
And rises inside the floating treatment tank 3.
For this reason, the floating of the flocs F on the surface of the floating treatment tank 3 can be smoothly promoted. According to this embodiment, the flocs F can be removed more efficiently, and the processing time can be further reduced. Can be achieved. Further, in the present embodiment, the membrane module 21 is disposed below the inlet 13 of the raw water in the floating processing tank 3, and flocs F that aggregate and float from the introduced raw water flow into the membrane module 21. Can be avoided. For this reason,
Such flocks F can be prevented from sticking to the surface of the hollow fiber membrane of the membrane module 21 to cause clogging, so that more stable membrane filtration can be performed.

Further, in the present embodiment, an inclined plate 31 is disposed above the membrane module 21 in the floating treatment tank 3.
Thereby, the treated raw water introduced from the inlet 13 and the treated raw water from which the floc F has been removed are separated to some extent. Therefore, it is possible to prevent a situation in which the treated raw water from which the floc F has not been sufficiently removed flows into the vicinity of the membrane module 21, and according to the present embodiment, it is possible to promote a more stable membrane filtration process. The advantage is also obtained. During the treatment, the membrane module 21 is constantly or intermittently washed by the aerator 32, and further, the washing water passage 23 connected to the drainage passage 22.
The backflow of the washing water from the
Since the backwashing can be performed, the membrane filtration performance of the membrane module 21 can be maintained for a long time.
Note that, instead of the empty washing of the membrane module 21, washing by injection of pressurized water (air saturated water) may be performed.

FIGS. 2 and 3 show a second embodiment of the present invention. The same reference numerals are assigned to components common to those of the first embodiment shown in FIG. Omitted. In the present embodiment, the levitation processing tank 3 of the levitation processing apparatus 1 is formed in a cylindrical shape, and the inflow path 14 of the raw water for treatment extends to the center of the levitation processing tank 3, and the inlet 13 opens upward. It is arranged to be. A cylindrical guide plate 16 is disposed around the inlet 13 so as to extend in the up-down direction. Further, the membrane module 21 of the membrane filtration device 2 is formed in an annular shape so as to surround the guide plate 16. Are located in In this embodiment, the inclined plate 31 and the aerator 3 are arranged in accordance with the arrangement of the membrane modules 21.
2 are also arranged in an annular shape.
It is formed in a funnel shape that is separated from the center on the third side and moves upward toward the outer peripheral side. In addition, the collection device 4 of the levitation processing apparatus 1 in the present embodiment is configured by a scraping plate 41 that rotates around the axis of the cylindrical levitation processing tank 3.
A type in which the flocs F floating on the surface of the floating treatment tank 3 are attracted and collected is used. The raw water for treatment and the pressurized water may be separately introduced into the floating treatment tank 3 as in the first embodiment.

Thus, in the water treatment apparatus having such a configuration, the membrane module 21 of the membrane filtration device 2 is disposed in the levitation treatment tank 3 of the levitation treatment device 1 and, as shown in FIG. The same effect as that of the embodiment can be obtained.
Further, in this embodiment, the flocks F of the raw water introduced from the inlet 13 are spread from the center of the floating processing tank 3 to the outer peripheral side while rising isotropically, and float uniformly on the surface of the floating processing tank 3. I do. Therefore, according to the present embodiment, it is possible to more efficiently remove the floc F, and it is possible to obtain an advantage that the processing time can be further reduced.

FIG. 4 shows a third embodiment of the present invention. As in the case of the second embodiment, the first embodiment shown in FIG.
The same components as those of the embodiment are denoted by the same reference numerals.
In this embodiment, the floating processing tank 3 of the floating processing apparatus 1
The two processing chambers 43 and 44 communicate with each other at the top through the second processing chamber 2. The side wall of one of the processing chambers 43 is provided with an inlet 13 for raw water to be processed, and the other processing chamber 44 is provided with membrane filtration. It is characterized in that the membrane module 21 of the device 2 is provided. Here, the other processing chamber 44
Is formed so as to have a larger capacity than one of the processing chambers 43, and the guide plate 16 extending in the vertical direction is disposed in the one of the processing chambers 43, while the guide plate 16 is provided in the other of the processing chambers 44. An inclined plate 31 is arranged above the membrane module 21 and an aerator 32 is arranged below the membrane module 21. Further, the height of the partition wall 42 is set so as to exceed the upper surface of the membrane module 21. In the present embodiment, the membrane module 21 is not disposed below the inlet 13 of the raw water as in the first embodiment, and the lower surface of the membrane module 21 and the inlet 13 are substantially at the same height. It is set to be. Also in the third embodiment, the raw water to be treated and the pressurized water may be separately introduced into the floating treatment tank 3.

In the present embodiment, the raw water is introduced from the inlet 13 into one of the processing chambers 43 of the floating processing tank 3, where the floc F is formed and rises inside the one processing chamber 43. Then, it floats on the surface of the floating treatment tank 3. Then, the flocs F that have floated are collected and removed by the collecting device 4, while the treated raw water from which the flocs F have been removed flows into the other processing chamber 44 from above the partition 42 and is subjected to membrane filtration by the membrane module 21. And discharged as treated water. Thus, also in this embodiment,
Since the membrane module 21 of the membrane filtration device 2 is disposed in the flotation tank 3 of the flotation device 1, the same effects as in the first embodiment can be obtained. In this embodiment,
Since one processing chamber 43 in which the inlet 3 is provided and the other processing chamber 44 in which the membrane module 21 is disposed are separated by the partition wall 42, the raw water introduced into the floating processing tank 3 is directly transferred to the membrane module 21. It is possible to more reliably prevent the water from flowing into the space. Thus, the treated raw water from which the floc F has been sufficiently removed can be subjected to the membrane filtration treatment, so that the treatment efficiency is further improved and the clogging of the hollow fiber membrane of the membrane module 21 can be further suppressed. Becomes

Further, since the raw water thus introduced is prevented from flowing directly into the membrane module 21 by the partition wall 42, in this embodiment, the inlet 13 of the raw water is connected to the membrane module 21 as described above. , Or at a position lower than the membrane module 21. As a result, the height of the floating treatment tank 3 can be kept relatively low, and according to this embodiment, it is possible to provide a more compact water purification apparatus, and further space saving can be achieved. There is also the advantage of being able to do so. Note that the membrane module 21 may be a collection of many hollow fiber membranes with one end closed. Also,
The membrane filtration device 2 may be an immersion type external pressure cross flow.

[0021]

As described above, according to the present invention, the processing raw water introduced into the floating processing tank of the floating processing apparatus is removed by floating the flocs, and the processing raw water from which the flocs have been removed is the same floating. The membrane is filtered and cleaned by a membrane module of a membrane filtration device arranged in the treatment tank. For this reason, the installation area of the water purification treatment device can be reduced to save space, and the treated raw water from which flocs have been removed is continuously subjected to membrane filtration, so that the treatment time can be significantly reduced. It becomes possible. Also, by removing the flocs by levitation processing in this way,
A highly versatile water purification treatment that can reliably and efficiently remove flocs of relatively light organic matter with a small density, so that it can sufficiently cope with treated raw water containing many such organic matter components. A device can be provided. In addition, the membrane module is
Is located below the inlet of treated raw water
Flocs flocculate from the introduced treated raw water
Clogging can be prevented from flowing into the membrane module
It is possible to perform more stable membrane filtration processing by preventing balls.
You. Also, the membrane module is covered and hidden above the membrane module.
Since the inclined plate is arranged as described above, a more stable membrane
Filtration can be promoted .

[Brief description of the drawings]

FIG. 1 is a side sectional view showing a first embodiment of the present invention.

FIG. 2 is a side sectional view showing a second embodiment of the present invention.

FIG. 3 is a sectional view taken along the line XX of the second embodiment shown in FIG. 2;

FIG. 4 is a side sectional view showing a third embodiment of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 Floating treatment device 2 Membrane filtration device 3 Floating treatment tank 4 Recovery device 13 Inlet 14 Inflow path of raw water for treatment 15 Pressurized water path 16 Guide plate 21 Membrane module 22 Drainage path 32 Aerator 42 Partition walls 43,44 Processing chamber F Flock

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-55-137081 (JP, A) JP-A-5-192659 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C02F 1/24 C02F 1/44 B01D 61/00-65/10 C02F 11/00-11/20

Claims (4)

(57) [Claims] 1. A flotation treatment apparatus for mixing pressurized water into treated raw water to float flocs in the treated raw water in a flotation treatment tank, and filtering the treated raw water from which the flocs have been floated and separated by the floating treatment apparatus using a membrane module. made by and a membrane filtering device, the membrane module by the floating process tank
And a water purification treatment device, which is disposed below the inlet of the treated raw water . 2. Raw water treated by mixing pressurized water into raw water treated
Floating treatment device that floats flocks in a levitation treatment tank
And the flock was floated and separated by this floating treatment device.
A membrane filtration device that filters the treated raw water with a membrane module
And the membrane module is installed in the flotation tank.
Being disposed and above the membrane module.
Note that the inclined plate is provided so as to cover the
Water purification equipment to be a feature. 3. An inlet for the treated raw water is disposed so as to open upward substantially at the center of the floating treatment tank, and the membrane module is disposed annularly so as to surround the inlet. The water purification treatment device according to claim 2 , wherein: 4. The floating processing tank is composed of two processing chambers whose upper parts communicate with each other via a partition, and one of the processing chambers is provided with an inlet for the raw water, and the membrane module is used for the other processing chamber. The water purification apparatus according to claim 2 , wherein the water purification apparatus is disposed in a chamber.